Housing Of Glass-ceramic Insulation For Vacuum Switch Tube

Glass ceramics which is suitable for making insulating enclosure of the vacuum interrupter,the procedure finishing glass ceramics molding and with the metal sealing at the same time, and the treatment procedure of the metal are researched emphasisly in this thesis.In this thesis, it is studied that the Li2O-Al2O3-SiO2 system glass ceramics of high expansion which can be a match for the iron nickel alloy (485 alloy ) with 102×10-7/℃expansion coefficient, and influence of the change of every group composition on performance of glass ceramics. A best composition range of the glass ceramics (Wt%),Li2O:10～14%,Al2O3:4～6%,SiO2:68～76%,K2O:2～5%,B2O3:2～5%,P2O5:2～3%, is confirmed. Typical composition is 5# dispensation as following(Wt%),Li2O:12.8%,Al2O3:5.0%,SiO2:72.0%,K2O:4.6%,B2O3:3.1%,P2O5:2.5%.The influence of change of the 5# nuclearing and the crystallizing on performance are researched, and the reason causing the influence are carried on analysis and discussion.A reasonable crystallizing heat treatment of 5# is established,the procedure is nuclearing at 620℃for an hour, crystallizing at 840℃for 2 hours. The expansion coefficient of the glass ceramics to be made is 96×10-7/℃,bending strength with 297 MPa, and the electric insulating ability,vacuum gettering performance , fire-resistant degree can meet the needs for vacuum interrupter enclosure. The molding and sealing of the glass ceramics are finished at the same time, by means of designing the special centrifugal molding machine and special mould.Then the enclosure is put into the muffle furnace where it would be crystallized,thus the production process and production cycle are greatly reduced. The surface treatment of the sealing metal is researched, especially the dispensation of sealing glass on the metal and the thickness of the sealing glass.The dispensation of the sealing glass FJ-4 with expansion coefficient of 92×10-7/℃is as following (Wt% ), Li2O: 0.6%, Al2O3: 5.0%, SiO2: 67.5%, K2O: 7.0%, Na2O: 12.0%, BaO: 12.0%, F: 0.9%. The FJ-4 and the 485 alloy have very fine soakage. When the thickness of sealing glass is 0.08～0.12 mm, the sealing strength is very high and. the air tightness is good.The 485 alloy which the surface is dealed with...